A flash memory or other storage media of a terminal stores executable image files. Generally, only one group of image files, that is, one group of available versions, are stored in the terminal, where the versions are replaced during upgrade. However, an EM wireless network access module, which serves as a product pattern of the terminal, is generally integrated into a notebook computer and is used for 3G (3rd-generation, third generation mobile communication technology) network access of the notebook computer. Because a user who buys a notebook computer can freely select networks of a plurality of operators, the EM wireless network access module also needs to support access to the networks of a plurality of operators
However, because different operators have different program requirements, when the user accesses an operator network, the user must have an admission test version of the operator to get authorized access to the operator network. Therefore, the EM wireless network access module with only one group of available versions cannot support access to the networks of a plurality of operators. Therefore, how to effectively store a plurality of operator versions and how to dynamically switch between versions and dynamically select a version have become issues that expect to be solved in this field.